It was already known that mutations to the DMR1 gene affect Arabidopsis’ resistance to the biotrophic pathogens Hyaloperonospora arabidopsidis and Oidium neolycopersici. In this BMC Plant Biology paper, Nelly Brewer, Nathaniel Hawkins and Kim Hammond-Kosack from Rothamsted Research instead investigate the effects of these mutations on resistance to the ascomycete pathogens Fusarium culmorum and F. graminearum.

Working with collaborators in Canada, Bill Finch-Savage and Steven Footitt from the University of Warwick’s Crop Centre present the findings of a study to investigate natural variation in the expression of genes involved in chromatin remodeling in two Arabidopsis ecotypes. Several key observations were made, including changes detected in the histone modifications H3K4me3 and H3K27me3 of the DOG1 gene during dormancy cycling, leading to the proposal that these histone marks serve as a thermal sensing mechanism during dormancy cycling in preparation for light repression of dormancy.

David Twell from the University of Leicester was involved in this study with Dutch colleagues from Radboud University Nijmegen. The group explored the processes taking place during pollen hydration in Arabidopsis; the step in pollination before emergence of the pollen tube. Expression of the gene BURSTING POLLEN (BUP) was found to be essential for the correct organisation of a ‘germination plaque’ – an intine-like structure consisting of cellulose, callose and party de-esterified pectin – which provides passage for the emerging pollen tube.

In a collaboration with scientists based in China, Fang-Jie Zhao and Yi Chen (Rothamsted Research), and new GARNet Chair David Salt (University of Aberdeen) carried out genome-wide association mapping in Arabidopsis in order to learn more about natural variation in the genetic control of the reduction of arsenate to arsenite. Understanding the control of this chemical reaction, and the extent to which inorganic arsenic accumulates in crops such as rice, is key to reducing the carcinogenic risk to human health. Analysis revealed a new arsenate reductase enzyme, High Arsenic Content 1 (HAC1).

When transferred from low light conditions to high light conditions, mature plant leaves typically increase their photosynthetic capacity via expression of GPT2. In this study, researchers from Germany and the University of Manchester used wild type and GPT2 knockout plants to try and work out how and why this happens.